Bliss was operating a Subaru Outback when it merged from Mount Herman Station Road (Route 142) onto Route 10, where it was struck broadside by a southbound SUV on Route 10, according to Mary Carey, a spokesman for District Attorney David E. Sullivan.

A passenger in the Subaru, Rita Corbin, of Hinsdale, N.H., was being treated for serious injuries at the University of Massachusetts Memorial Medical Center in Worcester, Carey said.

Five people in the SUV, including the driver, 19-year-old Nichole Trovato of West Townsend, Mass., were treated at Vermont's Brattleboro Memorial Hospital and later released.

Bernardston police and firefighters from Bernardston and Northfield initially responded.